More than 600,000 people have signed a petition calling for President Trump's impeachment as a poll indicates 40 percent of those queried would favor his ouster. Above, demonstrators call for impeachment in a protest against Trump's travel ban at Los Angeles International Airport, Jan. 28, 2017. Patrick T. Fallon/Reuters

Even as the clamor for President Donald Trump’s impeachment grows and public protest against his presidency intensifies, Democrats seem divided on the question of impeachment in an almost catch-22 situation.

Trump began his first week in office with a 36 percent approval rating, the lowest for any new president. His overall average rating from over a dozen or so polls has since wavered at about 45 percent approving and 50 percent disapproving.

However, some Democrats have urged caution in recent days about moving forward with impeachment proceedings without further evidence of misconduct, Politico reported Sunday. While there are several issues that could potentially cause trouble for Trump, including a potential conflict of interest over his financial ties, his immigration travel ban and his alleged ties to Russia, presidents can’t be impeached for their unpopularity.

"When and if he breaks the law, that is when something like that would come up. But that's not the subject of today," Democratic Leader Nancy Pelosi said earlier this month.

California Rep. Eric Swalwell, a member of the House Permanent Select Committee on Intelligence, and U.S. Rep. Brendan Boyle of Pennsylvania have also urged Democrats to hold off. “Before you can use the ‘I’ word, you really need to collect all the facts…the ‘I’ word we should be focused on is 'investigations’," he said.

Part of the hesitation is the concern that an “overzealous” opposition may lead to galvanizing more support for Trump. Republicans in both the GOP House and Senate campaign wings have reportedly already responded to criticism with fundraising pleas to defend the president.

“No president has EVER endured the level of disrespect shown to President Trump. (It’s sickening) Unprecedented obstruction from the left on his cabinet nominees. Mockery and scorn from the liberal media. And now the liberal elite are calling for his impeachment … IN HIS FIRST MONTH,” read one National Republican Senatorial Committee email from last week, according to Politico.

That's not to say Democrats aren't taking any action against the Trump White House. Many are backing an investigation from the Republican-led Senate Intelligence Committee into Trump’s ties to Russia.

But for Trump's fierest opponents, that's not enough. The Democratic National Committee, for example, has called Trump's coziness with Russia “bigger than Watergate" and demanded an independent, 9/11-style commission into the White House.

Meanwhile, Democratic leaders such as California Rep. Maxine Waters, Maryland Rep. Jamie Raskin and Texas Rep. Joaquin Castro have publicly called for impeachment proceedings to be initiated against Trump.